Can We Reduce Frame Rate to 15 Images per Second in Pediatric Videofluoroscopic Swallow Studies?

The Impact of Videofluoroscopic Pulse Rate on Duration and Kinematic Measures in Infants and Adults with Feeding and Swallowing Disorders

This investigation assessed the impact of temporal resolution during a videofluoroscopic evaluation of swallowing (VFSS) on measures of duration and kinematics. Thirty adult and ten infant swallow studies, all acquired at 30 frames and 30 pulses per second, were obtained from a New Mexico hospital. All swallow studies were altered to simulate 15 and 5 pulses per second. Duration measures included pharyngeal response time, duration of upper esophageal sphincter (UES) opening, velopharyngeal closure duration and total swallow duration. Kinematic measures were assessed in adults only and included peak hyoid position and extent of UES opening during the swallow. Analysis of outcome measures was performed and compared across the three temporal resolutions (30, 15, and 5 pulses per second). For data points where normative values are available, we evaluated the impact of temporal resolution on clinical determination (i.e., did a change in pulse rate alter the clinical classification). Kinematic and duration measures were altered with changes in pulse rate and these changes increased as temporal resolution decreased. For outcome measures where normative values are available, accuracy of clinical determination decreased with decreased pulse rate. Temporal resolution impacts duration and kinematic measures. However, the direction of these changes is unpredictable, indicating sensitivity and specificity are both affected. Without a predictable impact, the use of lower pulse rates may alter clinical impressions and treatment recommendations yielding inappropriate treatment goals and treatment duration.

Influence of frame rate in detecting oropharyngeal aspiration in paediatric videofluoroscopic swallow studies - An observational study

OBJECTIVES

The videofluoroscopic swallow study (VFSS), currently the gold standard for assessing aspiration in children, incurs radiation. Adhering to the ALARA principle is crucial in minimising radiation dose whilst obtaining accurate diagnostic information in children. International adult VFSS guidelines recommend a capture rate of 30 frames per second (fps). Higher capture rates increase radiation yet there is limited evidence on best practice VFSS capture rates in children, particularly on thin fluid consistency-the fastest viscosity with the highest potential for missed aspiration on slower capture rates. We aimed to determine if image acquisition at 30fps versus 15fps alters the accuracy of detecting aspiration when assessing thin fluids during paediatric VFSS.

MATERIALS & METHODS

Seventeen speech language pathologists (SLPs) blindly rated a total of 2,356 swallow loops for the presence/absence of aspiration from VFSS recordings of 13 infants/children drinking thin fluids. 76 swallow loops were randomly presented at 15 versus 30fps, on two occasions. Area under receiver operating curve (aROCs) was used to compare the accuracy of aspiration ratings at 15 versus 30fps compared to a comparison set. The intraclass correlation coefficient (ICC) was used to examine rater reliability.

RESULTS

Accuracy for detecting aspiration was near-identical at 15fps (aROC:0.97; 95%CI:0.96-0.97) and 30fps (0.96; 95%CI 0.96-0.97). Good inter-rater (ICC:0.82; 95%CI:0.72-0.89) and intra-rater reliability among the raters (ICC:0.89; 95%CI:0.82-0.93) was found.

CONCLUSION

Using 15fps in paediatric VFSS when assessing thin fluid consistency aspiration provides a similar detection rate to using 30fps. As 15fps would have a lower radiation dose than 30fps, we recommend using 15fps when undertaking VFSS in children.

CLINICAL RELEVANCE STATEMENT

Adhering to the ALARA principles, a capture rate of 15fps should be used in paediatric VFSS for assessment on thin fluids.

Videofluoroscopic Swallowing Study Features and Resting-State Functional MRI Brain Activity for Assessing Swallowing Differences in Patients with Mild Cognitive Impairment and Risk of Dysphagia

To examine the swallowing characteristics in patients with mild cognitive impairment (MCI) and dysphagia risk and explore brain activity changes using regional homogeneity (ReHo) with resting-state functional magnetic resonance imaging (rs-fMRI). We included 28 patients with MCI and dysphagia risk and 17 age-matched older adults. All participants underwent neurological, cognitive examinations, and a videofluoroscopic swallowing study (VFSS). We quantitatively analyzed the VFSS temporal and kinetic parameters of the 5- and 10-mL swallows. The participants underwent rs-fMRI, and the ReHo values were calculated. Differences in the swallowing physiology and rs-fMRI findings between participants with MCI and controls were analyzed. Correlation analyses were also conducted. Compared to the control group, patients with MCI and dysphagia risk had lower global cognition scores, longer 10-mL oral transit times (OTTs), and lower executive function scores. ReHo in the bilateral inferior occipital lobes (IOLs) and left prefrontal lobe decreased in patients with MCI and dysphagia risk compared to participants in the control group. In patients with MCI, the 10-mL OTT was negatively correlated with the Montreal Cognitive Assessment (MoCA) score, and the ReHo values were positive correlated with quantitative temporal swallowing measurements using canonical correlation analysis. Mediation analysis revealed that the ReHo values of the left and right IOL acted as significant mediators between the MoCA score and the 10-mL OTT. We found that individuals with MCI and dysphagia risk, verified by reduced MoCA scores, demonstrated prolonged OTTs when swallowing larger boluses compared with age-matched controls. There was a negative correlation between the MoCA score and 10-mL OTT, which was partially mediated by the left and right IOL ReHo values, suggesting that functional changes in the IOLs and left prefrontal lobe associated with oral swallowing status and cognitive level in individuals with MCI and dysphagia risk.

Using an Automated Speech Recognition Approach to Differentiate Between Normal and Aspirating Swallowing Sounds Recorded from Digital Cervical Auscultation in Children

Use of machine learning to accurately detect aspirating swallowing sounds in children is an evolving field. Previously reported classifiers for the detection of aspirating swallowing sounds in children have reported sensitivities between 79 and 89%. This study aimed to investigate the accuracy of using an automatic speaker recognition approach to differentiate between normal and aspirating swallowing sounds recorded from digital cervical auscultation in children. We analysed 106 normal swallows from 23 healthy children (median 13 months; 52.1% male) and 18 aspirating swallows from 18 children (median 10.5 months; 61.1% male) who underwent concurrent videofluoroscopic swallow studies with digital cervical auscultation. All swallowing sounds were on thin fluids. A support vector machine classifier with a polynomial kernel was trained on feature vectors that comprised the mean and standard deviation of spectral subband centroids extracted from each swallowing sound in the training set. The trained support vector machine was then used to classify swallowing sounds in the test set. We found high accuracy in the differentiation of aspirating and normal swallowing sounds with 98% overall accuracy. Sensitivity for the detection of aspiration and normal swallowing sounds were 89% and 100%, respectively. There were consistent differences in time, power spectral density and spectral subband centroid features between aspirating and normal swallowing sounds in children. This study provides preliminary research evidence that aspirating and normal swallowing sounds in children can be differentiated accurately using machine learning techniques.

Surgically Acquired Vocal Cord Palsy in Infants and Children with Congenital Heart Disease (CHD): Description of Feeding Outcomes

Impaired swallowing in infants can impact upon the ability to feed orally, often resulting in dependency on supplementary feeding. Such difficulties can lead to an increased burden of care and associated costs. The primary aim of this study was to investigate the impact of vocal cord palsy (VCP), acquired intraoperatively during cardiac surgery, on the feeding outcomes of infants at a tertiary metropolitan children's hospital. An additional aim was to obtain preliminary information on the impact of feeding difficulties in this group on the quality of life of parents and families. A review of 48 patients who had been referred to the speech pathology service was undertaken. Participants presented with heterogeneous cardiac diagnoses, and had an initial Videofluoroscopic Swallow Study (VFSS) at a median corrected age of 3.6 weeks. Sixty percent of participants presented with silent aspiration on VFSS. Thirty percent of participants required supplementary tube feeding more than 6 months post-surgery. Six percent of participants with poor feeding progress and persistent aspiration required further surgical intervention to support nutrition. Findings revealed no significant relationship between participant factors and the presence of feeding difficulties, however, infants with concomitant genetic and syndromic conditions were found to be most at-risk for long-term feeding difficulties. Analysis of informal parent questionnaire responses indicated parents experienced stress and anxiety after their child's discharge. This was noted in regard to their child's feeding, which impacts quality of life across a number of domains. Findings of this study highlight the importance of communicating the potential feeding difficulties to parents of at-risk infants prior to cardiac surgery. This study further highlighted the importance of routine post-operative otorhinolaryngology examinations following high-risk surgeries, as well as speech pathology management for all infants and children identified with VCP. Post-operative input from appropriately trained Speech Pathologists is vital in assisting parents to support and mitigate their child's difficulties through the provision of early intervention for feeding difficulties.

Safety of Bottle-Feeding Under Nasal Respiratory Support in Preterm Lambs With and Without Tachypnoea

Aim: Convalescing preterm infants often require non-invasive respiratory support, such as nasal continuous positive airway pressure or high-flow nasal cannulas. One challenging milestone for preterm infants is achieving full oral feeding. Some teams fear nasal respiratory support might disrupt sucking–swallowing–breathing coordination and induce severe cardiorespiratory events. The main objective of this study was to assess the safety of oral feeding of preterm lambs on nasal respiratory support, with or without tachypnoea.

Methods: Sucking, swallowing and breathing functions, as well as electrocardiogram, oxygen haemoglobin saturation, arterial blood gases and videofluoroscopic swallowing study were recorded in 15 preterm lambs during bottle-feeding. Four randomly ordered conditions were studied: control, nasal continuous positive airway pressure (6 cmH₂O), high-flow nasal cannulas (7 L•min^–1), and high-flow nasal cannulas at 7 L•min^–1 at a tracheal pressure of 6 cmH₂O. The recordings were repeated on days 7–8 and 13–14 to assess the effect of maturation.

Results: None of the respiratory support impaired the safety or efficiency of oral feeding, even with tachypnoea. No respiratory support systematically impacted sucking–swallowing–breathing coordination, with or without tachypnoea. No effect of maturation was found.

Conclusion: This translational physiology study, uniquely conducted in a relevant animal model of preterm infant with respiratory impairment, shows that nasal respiratory support does not impact the safety or efficiency of bottle-feeding or sucking–swallowing–breathing coordination. These results suggest that clinical studies on bottle-feeding in preterm infants under nasal continuous positive airway pressure and/or high-flow nasal cannulas can be safely undertaken.

Dynamic MRI of swallowing: real-time volumetric imaging at 12 frames per second at 3 T

Objective

Dysphagia or difficulty in swallowing is a potentially hazardous clinical problem that needs regular monitoring. Real-time 2D MRI of swallowing is a promising radiation-free alternative to the current clinical standard: videofluoroscopy. However, aspiration may be missed if it occurs outside this single imaged slice. We therefore aimed to image swallowing in 3D real time at 12 frames per second (fps).

Materials and methods

At 3 T, three 3D real-time MRI acquisition approaches were compared to the 2D acquisition: an aligned stack-of-stars (SOS), and a rotated SOS with a golden-angle increment and with a tiny golden-angle increment. The optimal 3D acquisition was determined by computer simulations and phantom scans. Subsequently, five healthy volunteers were scanned and swallowing parameters were measured.

Results

Although the rotated SOS approaches resulted in better image quality in simulations, in practice, the aligned SOS performed best due to the limited number of slices. The four swallowing phases could be distinguished in 3D real-time MRI, even though the spatial blurring was stronger than in 2D. The swallowing parameters were similar between 2 and 3D.

Conclusion

At a spatial resolution of 2-by-2-by-6 mm with seven slices, swallowing can be imaged in 3D real time at a frame rate of 12 fps.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10334-021-00973-6.

Instrumental Swallowing Assessments in the Neonatal and Pediatric Populations: A Systematic Review

The scientific scope of swallowing disorders in the neonatal and pediatric populations is growing exponentially; however, the preponderance of evidence for evaluation protocols has been concentrated in non-instrumental evaluations creating a lack of research about protocols for instrumental swallowing assessment. Thus, the purpose of this study was to systematically review the literature to identify and to report protocols used in instrumental assessments through videofluoroscopic swallow study (VFSS) and fiberoptic endoscopic evaluation of swallowing (FEES) in the neonatal and pediatric populations to support clinical decision making. The search strategy was applied in five online databases, no filters were applied to restrict languages or publication dates and the gray literature was reviewed. PRISMA statement was used to guide the construction of this review. The studies included validated and unvalidated protocols, the validated protocols had their risk of bias estimated using the QUADAS-2. In total, 13 studies were included in the final review, of these eleven assessed through QUADAS-2, and two classified with low risk of bias. One study is in the process of standardization and validation of an instrumental assessment protocol for swallowing in bottle-fed infants through VFSS. Information about validity and reliability of published protocols for instrumental evaluation in the neonatal and pediatric populations is limited. Therefore, further research is needs to development studies aiming to standardize and validate protocols for instrumental assessments in these populations.

Assessment of pharyngeal motor function using a novel velopharyngeal squeeze maneuver and a novel endoscopic pharyngeal contraction grade scale in patients with dysphagia after radiotherapy for nasopharyngeal carcinoma

Background

To investigate a novel velopharyngeal squeeze maneuver (VPSM) and novel endoscopic pharyngeal contraction grade (EPCG) scale for the evaluation of pharyngeal motor function.

Methods

During endoscopic examination of 77 post‐irradiated nasopharyngeal carcinoma patients and control subjects, VPSM was rated and lateral pharyngeal wall movement graded with EPCG scale during swallowing. Pharyngeal constriction ratio (PCR) measured by videofluoroscopy was used for correlation.

Results

VPSM and EPCG scale showed almost perfect intra‐rater and inter‐rater reliability (Kappa: >0.90). VPSM was present in 61% of patients suggesting good pharyngeal motor function. VPSM was predictive of EPCG scale (Wald statistic = 29.99, p < 0.001). EPCG scale also correlated strongly with PCR (r: 0.812) and was predictive for aspiration (odds ratio: 22.14 [95% CI 5.01–97.89, p < 0.001]).

Conclusions

VPSM and EPCG scale are two novel tools to assess pharyngeal motor function, and both correlate well with pharyngeal contractility and aspiration.

[Clinicopathological characterization of children with dysphagia, family impact and health-related quality of life of their caregivers]

INTRODUCTION

Oropharyngeal dysphagia (DOF) without proper evaluation can be underdiagnosed in certain groups of the pediatric population. Meeting the needs of these patients can lead to an overload of their caregivers.

OBJECTIVES

To describe the epidemiological and clinical characteristics of the patients evaluated after starting a monographic DOF clinic (C-DOF) and study whether there are changes at the nutritional level, as well as the burden and impact that caregivers find on quality of life related to health (HRQOL).

MATERIAL AND METHODS

Descriptive observational study of patients evaluated in a C-DOF from its start-up. To evaluate HRQOL, an ad hoc survey adapted from the Swallowing Quality of Life Questionnaire of the adult population was designed.

RESULTS

103 patients were evaluated, 85.4% presenting some neurological disease. A videofluoroscopic study was performed in 51 patients (49.5%), reporting combined alterations in both the oral and pharyngeal phases in 64.7% of them. There was a directly proportional correlation between the severity of the DOF and the presence of aspirations, as well as with the patient's motor impairment. Regarding the anthropometric evaluation, there was a trend toward improvement in weight z-score (+0.14 SD), height (+0.17 SD) and BMI (+0.16 SD). Out of 46.2% of the caregivers reported that the DOF problem interfered negatively in the basic activities of daily life. The increase in HRQOL, after the evaluation in the monographic DOF clinic, was statistically significant overall.

CONCLUSIONS

The monographic DOF clinic provided specialized care, impacting positively at the nutritional status of patients, as well as perceived changes in HRQOL, with a probable impact on caregivers.

Nasal respiratory support and tachypnea and oral feeding in full-term newborn lambs

Newborn infants with respiratory difficulties frequently require nasal respiratory support such as nasal continuous positive airway pressure (nCPAP) or high-flow nasal cannulae (HFNC). Oral feeding of these infants under nasal respiratory support remains controversial out of fear of aspiration and cardiorespiratory events. The main objective of this study was to evaluate the safety of oral feeding under different types of nasal respiratory support in newborn lambs without or with tachypnea. Eight lambs aged 4-5 days were instrumented to record sucking, swallowing, respiration, ECG, oxygen saturation, and arterial blood gases. Each lamb was given two bottles of 30 mL of milk with a pause of 30 s under videofluoroscopy in four conditions [no respiratory support, nCPAP 6 cmH₂O, HFNC 7 L/min, HFNC_CPAP (= HFNC 7 L/min + CPAP 6 cmH₂O)] administered in random order. The study was conducted in random order over 2 days, with or without standardized tachypnea induced by thoracic compression with a blood pressure cuff. Generalized linear mixed models were used to compare the four nasal respiratory supports in terms of safety (cardiorespiratory events and aspiration), sucking-swallowing-breathing coordination, and efficacy of oral feeding. Results reveal that no nasal respiratory support impaired the safety of oral feeding. Most of the few laryngeal penetrations we observed occurred with HFNC_CPAP. Nasal CPAP modified sucking-swallowing-breathing coordination, whereas the efficiency of oral feeding decreased under HFNC_CPAP. Results were similar with or without tachypnea. In conclusion, oral feeding under nasal respiratory support is generally safe in a term lamb, even with tachypnea.NEW & NOTEWORTHY The practice of orally feeding newborns suffering from respiratory problems while on nCPAP or HFNC remains controversial for fear of triggering cardiorespiratory events or aspiration pneumonia, or aggravating chronic lung disease. The present results show that bottle-feeding is generally safe in full-term lambs under nasal respiratory support, both without and with tachypnea.

Increased viscosity of milk during infant feeding improves swallow safety through modifying sucking in an animal model

Infants experiencing frequent aspiration, the entry of milk into the airway, are often prescribed thickened fluids to improve swallow safety. However, research on the outcomes of thickened milk on infant feeding have been limited to documenting rates of aspiration and the rheologic properties of milk following thickening. As a result, we have little insight into the physiologic and behavioral mechanisms driving differences in performance during feeding on high viscosity milk. Understanding the physiologic and behavioral mechanisms driving variation in performance at different viscosities is especially critical, because the structures involved in feeding respond differently to sensory stimulation. We used infant pigs, a validated animal model for infant feeding, to test how the tongue, soft palate, and hyoid respond to changes in viscosity during sucking and swallowing, in addition to measuring swallow safety and bolus size. We found that the tongue exhibited substantive changes in its movements associated with thickened fluids during sucking and swallowing, but that pharyngeal transit time as well as hyoid and soft palate movements during swallowing were unaffected. This work demonstrates the integrated nature of infant feeding and that behaviors associated with sucking are more sensitive to sensorimotor feedback associated with changes in milk viscosity than those associated with the pharyngeal swallow, likely due to its reflexive nature.

Radiation exposure in modified barium swallow studies

PURPOSE OF REVIEW

The modified barium swallow study (MBSS) is an X-ray examination of swallowing used to detect the presence and type impairment, aspiration risk, and to develop intervention plans. In this review, we will cover the use of ionizing radiation in MBSSs and review recent literature concerning radiation exposure and cancer risks to patients undergoing MBSSs. Lastly, we will discuss the clinical implications of these findings.

RECENT FINDINGS

Recent literature confirms that the MBSS is a low-dose examination and that reducing pulse rate negatively impacts diagnostic accuracy. Importantly, cancer risks to adults undergoing MBSSs were also reported to be low.

SUMMARY

An adult undergoing MBSS using a standardized, valid protocol, like the Modified Barium Swallow Impairment Profile (MBSImP), has low-radiation exposure and very low associated cancer risks. MBSSs should be used whenever relevant to adult patient care without undue concern regarding radiation exposure. Children also have low radiation exposure from MBSSs; however, cancer risks from that exposure remain unknown. Best practices in radiation safety must always be followed. Reducing pulse rates in the adult or pediatric population to reduce radiation exposure is not a valid strategy because of the resulting reduction in diagnostic accuracy.

Current videofluoroscopy practice in the United Kingdom: A survey of imaging professionals

INTRODUCTION

Videofluoroscopy (VFSS) is a frequently used radiological investigation for dysphagia and is conducted within a radiology setting by speech and language therapists (SLTs) working alongside imaging personnel (radiologists and/or radiographers). Previous surveys of SLT practice have reported variability in VFSS protocols and procedures. The aim of this study was to explore current clinical practice for VFSS from the perspective of imaging personnel engaged in VFSS within the United Kingdom.

METHODS

A comprehensive online survey enabled exploration of current practices of imaging professionals. Target participants were diagnostic imaging personnel (radiographers and radiologists) with experience of working in VFSS clinics. Descriptive statistics describe and summarise the data alongside inferential statistics where appropriate.

RESULTS

54 survey participants represented 40 unique acute healthcare organisations in the UK, in addition to two respondents from the Republic of Ireland. The survey demonstrated high variance in clinical practice across all stages of the VFSS procedure. Clinicians were not always compliant with current UK guidelines and the roles and responsibilities of different professionals working within the clinics were often not clearly defined.

CONCLUSION

Further research is required to develop new international, interprofessional VFSS guidelines to standardise service delivery for VFSS, improving diagnostic accuracy, efficiency and patient experience.

IMPLICATIONS FOR PRACTICE

In the absence of VFSS guidelines for imaging personnel, practitioners should familiarise themselves with the UK Royal College of Speech and Language Therapists VFSS Position paper; IR (ME)R guidelines and DRLs for the client groups with which they work to guide clinics and improve practice. Clinicians should revisit protocols and clinical governance regarding safe practice in order to improve the quality of care within the VFSS clinic.

Sucking versus swallowing coordination, integration, and performance in preterm and term infants

Mammalian infants must be able to integrate the acquisition, transport, and swallowing of food to effectively feed. Understanding how these processes are coordinated is critical, as they have differences in neural control and sensitivity to perturbation. Despite this, most studies of infant feeding focus on isolated processes, resulting in a limited understanding of the role of sensorimotor integration in the different processes involved in infant feeding. This is especially problematic in the context of preterm infants, as they are considered to have pathophysiological brain development and often experience feeding difficulties. Here, we use an animal model to study how the different properties of food acquisition, transport, and swallowing differ between term and preterm infants longitudinally through infancy to understand which processes are sensitive to variation in the bolus being swallowed. We found that term infants are better able to acquire milk than preterm infants, and that properties of acquisition are strongly correlated with the size of the bolus being swallowed. In contrast, behaviors occurring during the pharyngeal swallow, such as hyoid and soft palate movements, show little to no correlation with bolus size. These results highlight the pathophysiological nature of the preterm brain and also demonstrate that behaviors occurring during oral transport are much more likely to respond to sensory intervention than those occurring during the "pharyngeal phase."NEW & NOTEWORTHY Physiological maturation of infant feeding is clinically and developmentally significant, but seldom examined as an integrated function. Using longitudinal high-speed videofluoroscopic data, we found that properties of sucking, such as the length of the suck, are more sensitive to swallow physiology than those associated with the pharyngeal swallow itself, such as hyoid excursion. Prematurity impacted the function and maturation of the feeding system, resulting in a physiology that fundamentally differs from term infants by weaning.

Segmentation of cervical intervertebral disks in videofluorography by CNN, multi-channelization and feature selection

PURPOSE

Dysphagia has a large impact on the society because it is a risk factor of malnutrition and aspiration pneumonia, and therefore, it is necessary to elucidate the entire mechanism of dysphagia. In this study, we propose a segmentation method of cervical intervertebral disks (CIDs) in videofluorography (VF) by use of patch-based convolutional neural network (CNN), our multi-channelization (MC) method and image feature selection.

METHODS

Twenty image filters are individually applied to a VF frame image to generate feature images. One color image, called a multi-channelized image, is generated by setting three selected feature images to its red, green and blue channels. Patch-based CNN is applied to the MC image, and the segmentation accuracy of CIDs is evaluated by the pixel-based F-measure. The combination of the three feature images is optimized by the simulated annealing method.

RESULTS

The proposed method was applied to actual VF dataset consisting of 19 patients and 39 healthy participants. The segmentation accuracy was 59.3% in the F-measure when Sobel and morphological top-hat filters were selected in MC, whereas it was 56.2% when original frame images were used.

CONCLUSION

The experimental results demonstrated that the proposed method was able to segment CIDs from actual VF and also that the MC method was able to increase the segmentation accuracy by approximately 3%. In this study, LeNet was used as CNN. One of our future tasks is to use other CNNs.